FIELD OF THE INVENTION
The present invention relates to heat exchangers, especially to so-called comfort heat exchangers, and in particular to comfort heat exchangers of the type used in the heating and air conditioning systems of automobiles.
Heat exchangers are used in a wide variety of end-uses. In some instances, the heat exchangers are large and the weight of the exchanger is only of minor importance. However, in other instances the size and weight of the heat exchanger is a significant factor. An example of the latter is in the automobile industry where there are strict and demanding operating requirements that the exchanger must meet but where both the size and weight of the exchanger are important, especially as the automobile manufacturing companies continue to seek to improve fuel efficiency by reducing the weight of automobiles.
One of the means to reduce the weight of heat exchangers is to fabricate the exchanger from polymeric material instead of from metal. However, in general, it is not possible to merely substitute polymer for metal. Fabrication techniques that have proven to be quite acceptable using metals tend to be inapplicable to polymers. Moreover, performance requirements tend to mean that many polymers may not be suitable for use in the form of heat exchangers.
With respect to automobiles, there are five types of heat exchangers that may be used viz. the engine coolant heat exchanger (which is usually referred to as the radiator), air conditioning radiator, oil cooling system, air intake after-cooler or intercooler for turbo-charged air intake systems and the system used to heat and/or air condition the vehicle i.e. the so-called comfort heat exchanger. Each system has different performance requirements, including with respect to heat and pressure and with respect to the type of fluid to be passed through or around the heat exchanger.
A heat exchanger, and parts thereof, fabricated from a thermoplastic polymer and of a type suitable for use as a comfort heat exchanger in an automobile or other vehicle has now been found.